CVE-2026-28085: ThemeREX Mahogany LFI Vulnerability

CVE-2026-28085 Overview

CVE-2026-28085 is a PHP Local File Inclusion (LFI) vulnerability affecting the ThemeREX Mahogany WordPress theme. The vulnerability stems from improper control of filename parameters used in PHP include/require statements, allowing attackers to include arbitrary local files from the server. This can lead to sensitive information disclosure, configuration file exposure, and potentially remote code execution if combined with other attack techniques.

Critical Impact

Unauthenticated attackers may exploit this LFI vulnerability to read sensitive server files, expose configuration data including database credentials, and potentially achieve code execution through log poisoning or other file inclusion techniques.

Affected Products

• ThemeREX Mahogany WordPress Theme versions up to and including 2.9
• WordPress installations using the vulnerable Mahogany theme
• Web servers hosting affected WordPress sites

Discovery Timeline

• 2026-03-05 - CVE-2026-28085 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-28085

Vulnerability Analysis

This vulnerability is classified under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program). The ThemeREX Mahogany theme fails to properly sanitize user-supplied input before using it in PHP include or require statements. This allows an attacker to manipulate file path parameters to include arbitrary files from the local filesystem.

Local File Inclusion vulnerabilities in WordPress themes are particularly dangerous because they can expose sensitive WordPress configuration files such as wp-config.php, which contains database credentials, authentication keys, and other critical security parameters. The network-accessible attack vector means that remote attackers can exploit this vulnerability without authentication, though exploitation requires some level of complexity to successfully craft the malicious request.

Root Cause

The root cause of CVE-2026-28085 lies in insufficient input validation and sanitization of user-controlled parameters that are subsequently passed to PHP's file inclusion functions (include, require, include_once, or require_once). The Mahogany theme accepts user input—potentially through URL parameters, POST data, or other request variables—and incorporates this input into file paths without adequately filtering directory traversal sequences or validating against an allowlist of permitted files.

Attack Vector

The attack is network-based and does not require authentication or user interaction. An attacker can craft malicious HTTP requests containing directory traversal sequences (such as ../) or direct file paths to include sensitive local files. The exploitation complexity is considered high due to the need for specific conditions or additional techniques to achieve maximum impact.

Successful exploitation typically involves:

1. Identifying the vulnerable parameter that accepts file path input
2. Crafting a request with directory traversal sequences to escape the intended directory
3. Targeting sensitive files such as /etc/passwd, wp-config.php, or server log files
4. Potentially combining with log poisoning techniques to achieve code execution

For detailed technical information about this vulnerability, refer to the Patchstack security advisory.

Detection Methods for CVE-2026-28085

Indicators of Compromise

• Unusual HTTP requests containing directory traversal patterns (../, ..%2f, ....//) targeting Mahogany theme files
• Access log entries showing attempts to include system files like /etc/passwd or wp-config.php
• Requests with encoded path traversal sequences targeting theme template files
• Abnormal file read operations logged by file integrity monitoring systems

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block directory traversal patterns in request parameters
• Monitor server access logs for requests containing path manipulation sequences targeting the Mahogany theme directory
• Deploy endpoint detection solutions to identify suspicious file access patterns on WordPress installations
• Configure SIEM alerts for multiple failed file inclusion attempts from the same source IP

Monitoring Recommendations

• Enable detailed logging for all WordPress theme file access operations
• Implement real-time monitoring of requests to /wp-content/themes/mahogany/ with suspicious parameters
• Set up alerts for any access attempts to sensitive configuration files from web application processes
• Monitor for outbound connections that may indicate successful exploitation and data exfiltration

How to Mitigate CVE-2026-28085

Immediate Actions Required

• Audit your WordPress installation to determine if the Mahogany theme is installed and identify the version in use
• If running version 2.9 or earlier, immediately implement the workarounds listed below until a patch is available
• Review server access logs for any indicators of exploitation attempts
• Consider temporarily disabling or replacing the Mahogany theme with a secure alternative

Patch Information

As of the last update to this CVE record, no official patch has been confirmed in the available data. Website administrators should monitor the Patchstack advisory for updates on patched versions. Contact ThemeREX directly for information about security updates.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules to block directory traversal and LFI attack patterns
• Restrict PHP's open_basedir directive to limit file access to the WordPress installation directory only
• Disable the Mahogany theme and switch to a secure alternative theme until a patch is available
• Implement strict input validation at the server level using .htaccess rules or server configuration

# Example Apache .htaccess rules to block common LFI patterns
# Add to WordPress root .htaccess file

<IfModule mod_rewrite.c>
    RewriteEngine On
    
    # Block directory traversal attempts
    RewriteCond %{QUERY_STRING} (\.\./|\.\.%2f|\.\.%5c) [NC,OR]
    RewriteCond %{QUERY_STRING} (etc/passwd|wp-config) [NC]
    RewriteRule .* - [F,L]
</IfModule>

# Restrict PHP open_basedir in php.ini or .user.ini
# open_basedir = /var/www/html/wordpress:/tmp